Wiktionary
n. A short medicated stick, typically containing alum, used to stop bleeding from small wounds (as in shaving).
Usage examples of "styptic pencil".
Perhaps his point was that his explanation might be cryptic, yes, but at least it was a concept we could grasp and to which we could cling, a familiar idea that kept our sanity from draining away, just as the alum in a styptic pencil could stop the blood flowing from a shaving cut.
At the precise moment in question, the barber will be applying a styptic pencil to this insignificant wound.
Across the ring, Blanchard's trainer was swabbing his eyebrows with a styptic pencil and applying tiny adhesive bandages to the flaps of skin hanging loose.
Gladden pressed gently with a styptic pencil, then she held the white pencil under cold running water, then applied it again.